Index: llvm/trunk/lib/Support/StringSaver.cpp
===================================================================
--- llvm/trunk/lib/Support/StringSaver.cpp
+++ llvm/trunk/lib/Support/StringSaver.cpp
@@ -13,7 +13,8 @@
 
 StringRef StringSaver::save(StringRef S) {
   char *P = Alloc.Allocate<char>(S.size() + 1);
-  memcpy(P, S.data(), S.size());
+  if (!S.empty())
+    memcpy(P, S.data(), S.size());
   P[S.size()] = '\0';
   return StringRef(P, S.size());
 }